It was something of a full-circle moment when Lucas Sims found out the Cincinnati Reds were trading him to the Red Sox on Tuesday. In June, the right-handed reliever had introduced a cutter into his pitch mix, in an attempt to befuddle a formidable slugger.

Rafael Devers.

“I pulled it out against Raffy in a situation (where) I was like, ‘Why not? Pull it out now.’ And it’s been a lot of help,” Sims said as he stood in his new clubhouse on Wednesday afternoon. “He got a sac-fly.”

Now, Sims and Devers are teammates, and for that, the reliever is grateful.

“When we went into the series to prepare, there’s not a lot of letdown throughout the lineup,” recalled Sims. “They grind their at-bats, it’s quality at-bats up and down through the lineup, and it’s a tough lineup to navigate for sure, so I’m glad to be on their side now.”

Sims, 30, arrived at the trade deadline bearing a 3.57 ERA and 1.42 WHIP over 43 appearances, with 40 strikeouts across 35 ⅓ innings. He ranks in the 96th MLB percentile in average exit velocity, and between 70-80th percentiles in Breaking Run Value, K%, expected batting average, hard-hit %, and chase %.

“Lucas, he’s a competitor,” Red Sox pitching coach Andrew Bailey told the Herald. “His slider is really, really good. He’s got a cutter that he’s been working on a little bit that we really like, to be deployed as a weapon in the zone, and obviously he’s got a plus-heater. So, the arsenal is there, and looking forward to having him be a part of this ‘pen moving forward.”

“The cutter, you see month-by-month the trends of usage go up this season, and I think there’s a correlation to the success that he’s having,” Bailey added.

Though Sims has only gone to the cutter 49 times this season, the pitch is proving to be a valuable addition to his repertoire. It averages 91.2 mph and reaches the strike zone 43% of the time, with 30 swings (61.2%) and 13 misses. It’s inducing weak contact, with a 71.5 mph average exit velocity. Used in 13 plate appearances, it’s yielded five strikeouts and just one hit, a single.

“It’s a new pitch but it’s an old pitch. I’ve thrown it before, and I’ve kind of always just holstered it,” Sims explained. “Past couple years, I’ve kind of had it, but I wasn’t quite sure how I wanted to implement it and how it would complement my stuff. So just kind of finding the right spot for it. I would still kind of play catch with it periodically. And then I got kind of comfortable with it, and I was like, seems like a good time to pull it out.”

What can the Red Sox and their fans expect from one of their newest arms?

“I take a lot of pride in being ready, in taking the ball, whatever situation that might be, with the intention of going out there and winning a baseball game for the Red Sox,” Sims said. “Ultimately, I’m just gonna lay it all out there. Every time I take the field, I give it all I got. I put every ounce of energy into going out there and getting as many outs as I can.”

He’s also something of a fan himself. Amidst what he described as “a wild 24 hours,” Sims said he was thrilled to land in Boston. “(I’m) fired up to play at Fenway. It’s one of my favorite ballparks to come to,” he said, then corrected himself, “It is my favorite ballpark to come to. And now to be able to call it home for the rest of the season, I’m very happy to be here.”

“We’re gonna be playing some meaningful baseball here in the next few months, with a real shot at winning a ring,” he said. “That’s what we expect. All my understanding is that that’s the expectations of this city and this fan base, and you know I’m here for it.”

As to what Sims told Bailey and Alex Cora in their initial conversations? “Call down, I’ll be ready.”

On Tuesday evening, Cora made that call, and Sims entered for his Red Sox debut, taking over for Brayan Bello with one out and runners on the corners in the seventh.

His first pitch for his new team? A cutter for a pop-out.

The pitch he used to get the Mariners to leave the bases loaded? A cutter.